Nomogram for predicting severe abdominal adhesions prior to definitive surgery in patients with anastomotic fistula post-small intestine resection: a cohort study

Background: This study aimed to develop and validate a nomogram for predicting the presence of severe intra-abdominal adhesions before definitive surgery (DS) for anastomotic fistula following small intestine resection (SIR). Methods: Patients were enrolled from January 2009 to October 2023 and were randomly divided (2:1) into development and validation cohorts. Predictors of severe adhesion were identified and integrated into a nomogram. The nomogram’s performance was evaluated through calibration, discrimination, and clinical utility. Results : A total of 414 patients were included, with 276 in the development cohort and 138 in the validation cohort. Severe adhesion was diagnosed in 54 (13%) patients, including 37 (13.4%) in the development cohort and 17 (12.3%) in the validation cohort ( p = 0.76). Five predictors were identified: Sequential Organ Failure Assessment (SOFA) score, duration of early-stage abdominal infection, preoperative albumin (Alb) < 35 g/L, visceral to subcutaneous fat area ratio, and preoperative C-reactive protein (CRP) > 10 mg/L. The nomogram demonstrated robust discrimination, with a Concordance Index (C-index) of 0.80 (95% CI 0.76-0.90) in internal validation, and was well-calibrated. In the validation cohort, the model maintained good discrimination (C-index = 0.79; 95% CI 0.67-0.94) and calibration. Decision curve analysis affirmed the nomogram’s clinical utility. Conclusion: This study introduces a practical nomogram for assessing the risk of severe abdominal adhesion prior to DS in patients undergoing surgery for anastomotic fistula after SIR.